We are upgrading our software, and two parts of the software work in
very different ways. In a bid to normalise the opening of a document,
we are trying to understand what the default, or at least, the
expected method would be.

When a user re-opens a project (after making some changes to the
project), one window tells them that there have been changes made,
and
asks if you want to save them before opening the projects (ala
Excel),
and the other just ignores the prompt to open a project (ala Word)
and
returns them to how they were.

I personally believe that the first route is the best, in terms of
user interaction, as they are actually told there have been changes
made.

I regard the second as a 'lazy' way of opening a project, with
respect
to the user not being told of changes, and the project not opening
the
previously saved version.